Improvement in artificial legs



UNTTED STATES PATENT Ormeae IMPROVEMENT IN ARTIFICIAL LEGS.

Specification forming part of Letters Patent No. 51,593, dated December19, 1865.

To all whom it may concern:

Be it known that I, GEORGE B. JEWETT, of Salem, in the county of Essexand State of Massachusetts, have made a new and useful invention havingreference to Artificial Legs; and I do hereby declare the same to befully described in the following specification and represented in theaccompanying drawings, of which- Figure l is a side elevation, Fig. 2 afront view, Fig. 3 a rear elevation, and Figs. 4 and 5 are longitudinalsections, of an artificial leg provided with or constructed inaccordance with my invention.

In cases of amputation just below the kneejoint, owing to the shortnessof the stump or to the contraction of the tendons, or both, perhaps, itbecomes necessary sometimes, for application of an artificial leg to thethigh and stump, to have it provided with a knee-bearing. As usuallyconstructed such legs have been clumsy, especially about the knee partthereof, the joint-being arranged entirely below the knee, whereby thetibia part of the leg is rendered shorter than that of the natural leg,and the knee-joint advanced beyond that of the natural leg while theperson is in either a sitting or a kneeling posture. Then, again, thethigh-socket has been constructed as a wooden case with an opening inthe rear for the stump to extend through.

With my improvement 1 am enabled to dispeusewith the wooden thigh-caseand employ in its place a belt or socket of leather or other proper softor pliable material, it being so made as to lace in front, whereby itmay be adjusted to the thigh of the wearer with any desirable amount ofpressure. The laced belt or socket may tllus be employed to relieve theknee of the person from much pressure that it would otherwise exert onthe kneerest.

With my invention the tibia can be brought into an acute angle with thethigh, so as to bring the foot back under the thigh, which is not thecase with the other artificial legs of the kind hereinbefore referredto.

With my improved artificial leg the knee of the wearer will be supportedby a padded rest or socket duly shaped to receive and it it.

In the drawings, A denotes the tibia-post, to which the foot B ishinged. This post is bifurcated, or has applied to its upper part twocurved metallic supporters or branches, C O, formed as represented, eachat'its upper end terminating in a flat head, a, provided with ashoulder, x, to bear against. l

A curved stirrup or band of metal, D, connected with two thigh -socketsupporters or branches, b b, which are formed and provided withshoulders c o, as shown in the drawings, is placed between the two tibiabranches C O, and isjointed to them by means of two cylindrical pins, EE, which are screwed into the stirrup or knee-socket supporter, extendinto and through the branches O O, and are also screwed into two lappingpieces, F F, which,in turn, are fastened by screws s s to the branchesI) b, the whole being as shown in the drawings. The short pin E of eachjoint has two male screws cut on it, as shown in Fig. 5, they projectingin opposite directions from the cylindrical part of such pin, which hasa bearing on the tibia branch C. One of the screws of the pin is screwedinto the stirrup D. The other screw of it has one of the lapping piecesF screwed on it. This lapping piece extends up alongside of the branchb, and is secured to it by screws. The lapping piece thus becomes aclamp-nut, which is kept from revolving by being lapped on and securedto the part b, and while such lapping piece is so fastened to the part bthejoint will be eftectually secured in place, and cannot be removedfrom its position by the part C while turning` on it. The said stirrupsupports a knee-rest, G, which is arranged within and fastened to it,and consists of a metallic plate duly padded on its upper surface, so asto t to the knee of the person by whom the artificial leg is to be worn.

To the two branches b b, made of spring-steel or other suitablematerial, a broad flexible belt, band, or socket, H, is secured, itbeing to go around the thigh of a person and so made as to lace in frontthereof, its lacing being shown at d.

The arrangement of the knee-rest and the joints on two opposite sidesthereof should be such as to bring such joints in, or about in, theprolongation of the axis of motion of the kneejoint of the wearer of theleg while supported by the knee-rest G.

Au elastic retracting strap or spring, I, is

connected with the knee-rest and the tibia-post, or arranged therewith,as shown in the drawings.

The particular mode of constructing each of the joints, of connectingthe tibia branches and the knee-rest stirrup and its extensions orbranehes,is one of great value and importance, as, while it renders thejoint very strong, it effeetually prevents the pin thereof from workingloose or being lost. The shoulders c x of each joint, when in contactwith each other, prevent the leg from being bent backward at theknee-joint.

Having thus described my improved artieial leg, what I claim therein asof my invention is as follows, viz:

l. In artificial legs designed for the treat ment of the kind of caseshereinbefore mentioned, the above-explained arrangement of the knee-joints with respect to the knee-rest Gr, such joints under sueharrangement being brought above thewbearing of the natural knee on therest, and so as to be in, or about in, the prolongation ofthe axis ofmotion ofthe knee.

2. Theimproved kneejoint, constructed substantially as described-viz.,with the joint-pin screwed into the two external parts ofthe joint, andwith one of such parts connected to the other by screws or theirequivalents.

3. The combination of the knee-rest stirrup or supporter D and itsthigh-belt-sustaining branches b b, with the tibia-post branches C Carranged as specified.

4. rlhe combination of the knee-rest Gr, its supporter D, the thigh-beltbranches b b, and the tibia-post branches G G, arranged as speciiied.

5. rlhe combination of the thigh-belt or ilexible lacing-socket H, theknee-rest G, the supporter D, and the branches b b and C C, hingedtogether and connected with the tibia-post, the whole beingsubstantially as hereinbefore explained.

6. The arrangement of the retractile strap with, or its applicationdirectly to, the kneerest, as described.

GEO. B. JEWETT.

Witnesses:

J AMES A. GILLIS, J. FRANKLIN BLY.

